Scaffolding and like construction

ABSTRACT

A clamp for securing releasably to large diameter pipes to serve as a support member for scaffolding, access ways or the like thereon. The clamp comprises a cross member having spaced apart legs provided with pivotally mounted feet to engage the pipe. A gripping element is provided to embrace the pipe and hold the cross member securely thereon. The gripping element may comprise a tensioned chain or alternatively a further, rigid cross member with pivoted feet adapted to engage the underside of the pipe, means being provided for drawing such member upwardly towards the cross member. Scaffolding may be erected on the cross member or walkways may be constructed, suspended from the cross member, on opposite sides of the pipe.

111' 3,872,947 [451 Man 25, 1975 1 SCAFFOLDING AND LIKE CONSTRUCTION [76] Inventor: John Henry Cranfield, 18 Rowan Rd., Sutton, Coldfield, England [22] Filed: Dec. 3, 1973 [21] Appl. No.: 421,132

[30] oreign Application Priority Data Dec. 9, 1972 UnitedKingdom 56950/72 [52] U.S. Cl 182/82, 182/150, 182/130, 248/65, 248/221 [51] Int. Cl. E04g 3/00 [58] Field of Search 182/82, 113, 129, 150, 182/130; 248/65, 221

[56] References Cited UNITED STATES PATENTS 1,993,320 3/1935 Dozier 182/187 2,117,008 5/1938 Oswalt 182/113 FOREIGN PATENTS OR APPLICATIONS 848,245 9/1952 Germany 182/214 Primary Examiner-Reinaldo P. Machado Attorney, Agent, or Firm-Parmelee, Miller, Welsh & Kratz [57] ABSTRACT L A clamp for securing releasably to large diameter pipes to serve as a support member for scaffolding, access ways or the like thereon. The clamp comprises a cross member having spaced apart legs provided with pivotally mounted feet to engage the pipe. A gripping element is provided to embrace the pipe and hold the cross member securely thereon. The gripping element may comprise a tensioned chain or alternatively a further, rigid cross member with pivoted feet adapted to engage the underside of the pipe, means being provided for drawing such member upwardly towards the cross member. Scaffolding may be erected on the cross member or walkways may be constructed, suspended from the cross member, on opposite sides of the pipe.

10 Claims, 4 Drawing; Figures 1 SCAFFOLDING AND LIKE CONSTRUCTION BACKGROUND OF THE INVENTION l. Field of the Invention.

This invention relates to scaffolding and like constructions for providing access during construction of, or maintenance work on, some structure on which the scaffolding is erected.

More particularly, the present invention is concerned with the erection of scaffolding, access ways, or the like on large diameter pipes of the kind from which marine oil drilling rigs are constructed.

2. Description of the Prior Art.

There is frequently a need for erection of scaffolding or access ways on such oil rigs both during and after their construction in order to provide access to various working areas, but due to the fact that such oil rigs are constructed largely from largely diameter pipes it is not readily possible to erect conventional scaffold assemblies or walkways thereon.

SUMMARY OF THE INVENTION According to the present invention we provide a clamp for securing releasably to large diameter pipes to serve as a support member for the scaffolding, access ways or the like thereon, the clamp comprising a cross member provided at spaced positions along its length with respective downwardly extending legs, pivotally mounted feet at the lower end of each leg adapted to engage the exterior of such a pipe, and a gripping leg adapted to engage the exterior of such a pipe, and a gripping element secured to said cross member at or adjacent to the ends thereof, and tensioning means operative between said gripping element and said cross member so that the cross member and the gripping element can embrace said pipe externally and secure the cross member thereto with the feet firmly engaging said pipe.

The gripping element may in one case comprise a chain or cable which is preferably attached at both ends to the cross member by respective tensioning means. Such tensioning means may comprise a bolt pivotally mounted on the cross member and co-operating with an internally threaded member to which the chain or cable is secured. Additional tensioning means may be provided intermediate the ends of the chain or cable, the latter then being formed in two or more separate lengths. Such additional tensioning means may be of similar form to the first mentioned tensioning means, or alternatively may comprise a nut and bolt assembly carrying two lugs to which sections of the chain or cable are secured.

It will be appreciated that with this arrangement the number of chain or cable sections can be varied to adapt the clamp for assembly with pipes having a wide range of diameters. Alternatively, a plurality of interchangeable flexible elements of differing lengths may be provided.

The chain or cable may, over at least part of its length, be covered with a sleeve of material, such as canvas or rubber, having a high coefficient of friction. Likewise, the feet may be equipped with friction pads. Alternatively, or in addition, a band of such material may be wrapped around the pipe where it is to be engaged by the feet and the flexible element.

In order specifically to adapt the cross member to serve as a support member for a scaffolding construction, it may, for example, be provided with a plurality of spigots or sockets for engagement with the lower end of upright scaffolding tubes. Alternatively, or additionally, suitable clamps or other fixing means may be provided for attaching horizontally extending scaffolding tubes, planks, battens. Also, upright members may be provided on the cross member for the attachment of horizontally extending scaffolding tubes to serve, for example, as handrails or other parts of a scaffolding construction.

In an alternative case, the gripping element may comprise a lower, rigid cross member provided with upwardly extending lugs having pivotally mounted feet at their upper ends adapted to engage the exterior of the pipe at positions generally opposed to the feet carried by said legs, respective tensioning means being pro vided at each end of the lower c ross member to urge the latter upwardly towards the upper cross member.

The lower cross member may be guided for movement towards and away from the upper cross member by'engagement with vertical members secured rigidly at opposite ends of the upper cross member. The vertical members may each afford a longitudinal slot in which is received a pin projecting endwise from the end of the lower cross member. Such pin may also serve part of a clamp to enable the lower cross member to be frictionally secured to the vertical members at selected positions along the length of the slots thereof.

The vertical member may be provided'with laterally outwardly extending supports on which battens may be laid to extend between adjacent clamps secured to the pipe thereby to enable walkeays to be formed on one or both sides of the pipe.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described by way of example with reference to the accompanying drawings wherein:

FIG. 1 is a perspective view of one form of friction clamp in accordance with the invention installed in position on a large diameter pipe,

FIG. 2 is a side view of one end of the friction clamp shown in FIG. 1,

FIG. 3 is a side view of a modification of the friction clamp of FIG. 1, and

FIG. 4 is a view similar to FIG. 3 of a further embodiment of friction clamp, showing the manner in which it is installed on pipes of different diameters.

DESCRIPTION OF THE PREFERRED EMBODIMENTS horizontally extending pipe which may have a diameter.

of between 3 feetand I0 feet. A belt 10 of rubber or similar material is wrapped around the pipe where it is to receive a friction clamp in accordance with the invention. Briefly, the clamp comprises a cross member 12, a pair of upright legs 14, pivotally mounted feet 16, at the lower ends of the legs, and a chain 18 which extends around the pipe and is connected to the cross member 12 by tensioning means as hereinafter described. The cross member 12 carries two upright members 13 to which horizontally extending guard rails 15 may be secured, and the cross member itself is adapted to receive the ends of horizontally extending battens 17, one of which is illustrated in FIG. I.

Referring now to FIG. 2, in which the clamp is shown in more detail, the cross member 12 consists ofa length of square-section tube'having a pair of vertically disposed plates secured thereto at each end. A rod 21 extends through aligned apertures in the plates 20 and is retained captive by means of washers 22 welded to the rod 21 outside the plates 20. The rod 21 is provided with an aperture through which extends the shankof a headed bolt 23, the head 24 of the bolt 23 lodging against the upper side of the rod 21. The bolt shank engages a nut 25 secured within the end of a tube 26 which is flattened at its opposite end and has a pair of plates 27 secured thereto. A nut and bolt 28 serves to secure the terminal link of the chain 18 between the plates 27.

It will be evident that rotation of the bolt 23 by means of its head 24 will adjust the axial position of the tube 26 and thereby serve to tension the chain 18.

Preferably, as illustrated in FIG. 1, similar tensioning means are provided at the opposite end of the cross member 12. However, it would alternatively be possible for the chain 18 to be secured directly to the cross member 12 at its other end.

The leg 14 comprises a circular section tube which passes through aligned apertures in the upper and lower sides of the cross member 12 and is welded thereto. A diagonal strut 11 extends between the leg 14 and the underside of the cross member 12. A pin 27 extends through aligned holes adjacent to the lower end of the leg 14 and carries a pair of plates 28 to which the foot plate 16 is secured. The foot plate 16 is thus free to swivel about the pin 27 and adapt an appropriate orientation which it engages the surface of the pipe.

In the particular embodiment illustrated in FIGS. 1 and 2, the cross member 12 carries a bar 29 at its upper side. This serves to locate horizontally extending battens 17 as illustrated in FIG. 1. The cross member 12 also carries the upright members 13 to which are attached V-sockets 30 whereby the guard rails 15 or other horizontally extending members may be secuted to the upright member 13.

In an alternative arrangement, the foot plates 16 may be equipped with friction pads at their underside, and the chain 18 may be provided with a sleeve of suitable friction material in order to avoid the necessity of wrapping a band of such material around the pipe itself.

FIG. 3 illustrates a modified arrangement in which like parts are given the same reference as in FIGS. 1 and 2. In this case, the foot plate 16 is shown as being provided with a friction pad 16a and the bolt 23 is shown secured directly to the cross member 12 in a non-pivotal manner. The chain is also divided into a number of sections, three sections 18a, 18b and 180 being shown. In addition to the tensioning means formed by bolt 23 and tube 26, further tensioning means are provided between adjacent chain sections. Such means comprise a bolt 31 extending through apertures in lugs 32 to which the ends of the chain sections are secured. The bolt 31 carries a nut 33 by means of which the chain sections may be tensioned. In this case, the chain sections preferably are equipped with sleeves of rubber or canvas as shown, and the lugs 32 may also be equipped with friction pads (not shown) where they engage the pipe.

The number of chain sections may be varied according to the diameter of the pipe on which the clamp is to be installed, and a similar expedient may be adopted for use with the embodiment shown in FIG. 1.

In a further alternative, the cross member 12 may be of telescopically extensible form, preferably comprising a central part and two outer parts which overlap the latter extenally. It will be understood that the various parts of the cross member 12 may be secured together by any suitable releasable means, such as bolts. This arrangement is particularly suitable where the tensioning bolts 23 are not pivotally attached to the cross member 12, since the length ofthe latter can be adjusted to suit the diameter of the pipe to which the clamp is to be attached.

The further embodiment shown in FIG. 4 is primarily intended for the provision of walkways on either side of the pipe on which it is installed, but it will be understood that itcan additionally serve as a support for scaffolding.

The friction clamp shown in FIG. 4 includes a cross member 42 carrying a pair of downwardly directed legs 44 each having pivotally connected thereto a respective foot 46 equipped with a friction pad 46a. The position of the legs 44 may be adjustable along the length of the cross member 42 if desired. At each end, the cross member 42 carries a respective dependant vertical member 48, each of which consists of two channel section members arranged with their webs spaced slightly apart and with their flanges directed away from one another so that a vertical slot is defined between the webs thereof. The channel section members are secured together by means of plates 49. The cross member 42 may be similarly constructed with the legs 44 received within a horizontal slot defined between two channel section members.

The clamp also includes a rigid lower cross member 50 having endwise projecting bolts 52 which extend through the slots ofthe vertical members 48 so that the lower cross member 50 is guided for movement towards and away from the upper cross member 42. Nuts 53 and washers 51 are provided on the free ends of the bolts 52 to enable the lower cross member 50 to be clamped to the vertical members 48 at selected positions along the length thereof.

The lower cross member 50, which may be constructed in a manner similar to the upper cross member 42, carries upwardly extending lugs 54 each provided with pivotally mounted feet 56 having friction pads 56a.

The lower cross member 50 is suspended from the upper cross member 42 by means of chains 58 equipped with tensioners 59 each in the form of a chain clutch so that the length of chain between the two cross members is effectively adjustable.

In use, the friction clamp is placed upon a pipe in the manner shown in FIG. 4 with the upper. and lower feet 46 and 56 engaging the pipe at points spaced about its periphery. The chains 58 are then tensioned so that the feet grip the pipe and then the nuts 53 are tightened to clamp the lower cross member 50 to the vertical members 48 in order to some extent to releive the tension on the chains.

The vertical members 48 each carry at their lower ends a respective outwardly directed support 60, each of which in the embodiment shown carry a handrail standard 61 and a clamp 62 for battens so that a walkway can be constructed along one or both sides of the pipe between successive clamps secured thereon.

It will be appreciated that friction clamps in accordance with the invention can be used with pipes of other than round section by virtue of the pivotal mounting of the feet and the flexibility of the gripping chain where used.

I claim: l. A clamp for securing releasably to large diameter pipes to serve as a support member for scaffolding, access ways or the like thereon, the clamp comprising a. a cross member, b. legs extending downwardly from said cross memher at spaced positions along the length thereof,

cf a respective foot mounted pivotally at the lower end of each said leg and adapted to engage the exterior of the pipe,

d. a gripping element secured to said cross member at or adjacent to the ends thereof, and

e. tensioning means operative between said gripping element and said cross member for collectively embracing said pipe externally and thereby securing the cross member to said pipe with said feet firmly engaging said pipe.

2. A clamp according to claim 1 wherein the gripping element comprises an elongated flexible member adapted to engage the pipe around a part of its periphery.

3. A clamp according to claim 2 wherein said elongated tlexible member is, over at least part of its length, covered with a sleeve of material having a high coefficient of friction.

4. A clamp according to claim 2 wherein said tensioning means comprises at least one bolt pivotally mounted on the cross member and a co-operating internally threaded member to which said gripping element is secured.

5. A clamp according to claim 2 wherein said flexible gripping elementis formed in two or more separate 6. lengths and said tensioning means is provided to operate between respective lengths thereof.

6. A clamp according to claim 1 wherein said gripping element comprises a. a lower, rigid cross member,

b. upwardly extending lugs carried by said lower cross member at positions spaced along the length thereof,

c. a respective foot pivotally mounted at the upper end of each of said lugs and adapted to engage the exterior of the pipe at positions generally opposed to the feet carried by said legs, and

d. said tensioning means being arranged to be operative between said two cross members at positions adjacent to the ends thereof.

7. A clamp according to claim 6 wherein means are provided for guiding movement of the lower cross member towards and away from-the upper cross memher.

8. A clamp according to claim 7 wherein said means comprise vertical members secured to the upper cross member at opposite ends thereof, and each of said vertical members affords a longitudinal slot, the lower cross member having a respective pin projecting enclwise therefrom at each of its ends, the pins engaging in said slots.

9. A clamp according to claim 8 wherein said pins carry clamping means for-clamping the lower cross member frictionally to the vertical members at selected positions along the length of the slot therein.

10. A clamp according to claim 8 wherein the vertical members are provided with laterally outwardly extending supports on which battens may be laid to extend between adjacent similar clamps secured to the pipe at spaced positions along the length thereof.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,872,947 Dated March a 1975 Inventor(s) John Henry Cranfield It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover page insert:

[73] Assignees Kwikform Limited, Warwick County,

England Signed and Scaled this Fifth Day of October 1976 [SEAL] A nest.-

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner of Pau'ms and Tradcmurkx UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,872,947 Dated March 25, 1975 lnventofls) John Henry Cranfield It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover page insert:

-- [73] Assignee: Kwikform Limited, Warwick County,

England Signed and Scaled this Fifth Day of October 1976 [SEAL] AIIGSI.

RUTH C. MASON C. MARSHALL DANN AIIPSIMR ffif (umrnissimzer uj'lalenrs and Trademarks 

1. A clamp for securing releasably to large diameter pipes to serve as a support member for scaffolding, access ways or the like thereon, the clamp comprising a. a cross member, b. legs extending downwardly from said cross member at spaced positions along the length thereof, c. a respective foot mounted pivotally at the lower end of each said leg and adapted to engage the exterior of the pipe, d. a gripping element secured to said cross member at or adjacent to the ends thereof, and e. tensioning means operative between said gripping element and said cross member for collectively embracing said pipe externally and thereby securing the cross member to said pipe with said feet firmly engaging said pipe.
 2. A clamp according to claim 1 wherein the gripping element comprises an elongated flexible member adapted to engage the pipe around a part of its periphery.
 3. A clamp according to claim 2 wherein said elongated flexible member is, over at least part of its length, covered with a sleeve of material having a high coefficient of friction.
 4. A clamp according to claim 2 wherein said tensioning means comprises at least one bolt pivotally mounted on the cross member and a co-operating internally threaded member to which said gripping element is secured.
 5. A clamp according to claim 2 wherein said fLexible gripping element is formed in two or more separate lengths and said tensioning means is provided to operate between respective lengths thereof.
 6. A clamp according to claim 1 wherein said gripping element comprises a. a lower, rigid cross member, b. upwardly extending lugs carried by said lower cross member at positions spaced along the length thereof, c. a respective foot pivotally mounted at the upper end of each of said lugs and adapted to engage the exterior of the pipe at positions generally opposed to the feet carried by said legs, and d. said tensioning means being arranged to be operative between said two cross members at positions adjacent to the ends thereof.
 7. A clamp according to claim 6 wherein means are provided for guiding movement of the lower cross member towards and away from the upper cross member.
 8. A clamp according to claim 7 wherein said means comprise vertical members secured to the upper cross member at opposite ends thereof, and each of said vertical members affords a longitudinal slot, the lower cross member having a respective pin projecting endwise therefrom at each of its ends, the pins engaging in said slots.
 9. A clamp according to claim 8 wherein said pins carry clamping means for clamping the lower cross member frictionally to the vertical members at selected positions along the length of the slot therein.
 10. A clamp according to claim 8 wherein the vertical members are provided with laterally outwardly extending supports on which battens may be laid to extend between adjacent similar clamps secured to the pipe at spaced positions along the length thereof. 